1. Field of the Invention
The present invention relates to an object recognizing apparatus and method for a vehicle and particularly to an object recognizing apparatus and method to be employed for a drive assist system of an automobile or for an autonomous running control system of an autonomous running vehicle.
2. Prior Arts
In order to compensate an operating sense of a vehicle driver when he passes through narrow roads with frequent obstacles such as walls, poles, guard rails, parked vehicles and the like, there has been developed an apparatus for detecting those obstacles by means of tactile sensors such as a corner pole, a contact switch and the like mounted on a vehicle.
Further, there has been developed a technique in which ultrasonic sensors are mounted on the side face or corners of the vehicle for measuring a distance to an obstacle and informing a vehicle driver of the measured distance.
Further, in recent years, there has been proposed a technology for not only detecting a distance to an obstacle but also recognizing the figure of the obstacle. As an example of such technology, the Applicant of the present invention discloses an obstacle recognition apparatus using a plurality of CCD cameras and a stereoscopic picture image processor for recognizing obstacles around the vehicle to inform the vehicle driver in Japanese Patent Application Laid-open No. Toku-Kai-Hei 5-114099. This obstacle recognition apparatus can not only recognize a direction and shape of an obstacle but also can obtain an exact distance to the obstacle.
In autonomous running vehicles, in order to avoid a collision to or a contact with obstacles during running, there is a technology in which existence or non-existence of obstacles is detected using an infrared sensor or an ultrasonic sensor and when an obstacle exists, such a control as stopping the vehicle is performed.
Further, according to a recent smart autonomous running control vehicle, using the aforementioned stereoscopic picture image processor for recognizing obstacles nearby the vehicle, it is possible to find a plurality of obstacles at the same time, to recognize the direction and figure of these obstacles and further to perform miscellaneous controls such as stopping the vehicle or guiding the vehicle in the direction where there is no obstacle.
However, the aforementioned obstacle recognition apparatus employing stereoscopic cameras has a problem that since it can recognize only obstacles coming into a field view of the cameras, for instance in case of installing cameras with a lens directed ahead of the vehicle, objects existing in the field view of cameras can be recognized but objects existing outside of the field view can not.
Accordingly, when the vehicle turns a corner, there is a possibility that the vehicle may bump an obstacle standing at the corner. To prevent this, it is readily considered that additional cameras are mounted for monitoring obstacles located on both sides of the vehicle, however, this idea is not acceptable because of an additional need for securing the location of cameras and a cost increase.
Particularly, in case of the autonomous running vehicle, for example, in case of a floor cleaning vehicle which does a cleaning work on a floor unmannedly, it is frequently required to make a delicate work around an obstacle. That is to say, the vehicle is required to have a capability of being able to recognize every obstacle therearound. In this case, it is not permissible for the same reason as in the above case to equip additional cameras and the like.
The present invention has been accomplished in consideration of these circumstances and it is an object of the present invention to provide an object recognizing apparatus capable of recognizing objects around the vehicle over a wide range without the use of additional cameras, ultrasonic sensors, photo sensors or other sophisticated object detecting devices. Such object recognizing apparatus comprises:
object detecting means for detecting a direction of objects and a distance distribution to the objects;
object recognizing means for recognizing the objects as a solid object based on the distance distribution and for calculating a relative position of the objects with respect to the vehicle;
object position memory means for memorizing the relative position of the objects with respect to the vehicle;
travelling amount calculating means for calculating a travelling amount including a travelling distance and a travelling direction of the vehicle; and
object positional information calculating means for calculating a new relative position of the objects with respect to the vehicle based on the relative position of the objects and the travelling amount of the vehicle and for updating the relative position memorized in the object position memory means with the new relative position of the objects.